Agricultural implements such as planters and fertilizers are commonly known in the agricultural industry. Such implements typically include a wheeled and elongated frame assembly having a plurality of row units mounted thereon for distributing particulate material as the implement is pulled across a field. Each row unit receives materials frown a common material hopper. To effect the delivery of materials, a series of elongated tubes or conduits pneumatically transfer material from the hopper to the individual row units.
To reduce the number of passes a farmer must make across a field and to increase implement efficiency, farm implement manufactures have been making larger and wider frame assemblies for the implements. By increasing the width of the frame assembly, the number of row units that can be mounted on the implement is likewise increased. As the width of the implement frame assembly has increased, however, transportation of the implement from field to field has become more difficult. Moreover, the increased width of the implement frame assembly inhibits its passage through barn doors as well as gates and fences surrounding the field.
Agricultural manufacturers have offered a variety of approaches to overcome the transportation problem inherent with such large agricultural implements. One of the more popular approaches involves dividing the implement frame assembly into a main section with one or more wing sections being hingedly or pivotally connected to one or both ends of the main section. Each section of the implement frame assembly has one or more row units mounted thereon. As is well known in the art, the pivotal connections allow each wing section to move either horizontally forwardly or horizontally rearwardly relative to the main section or vertically relative to the main section. In those implements wherein the wing sections are horizontally folded relative to the main section, the vertical axis about which the wing section moves is typically spaced inwardly from a distal end of the tool bar on the main section to minimize the width of the implement in a folded condition.
As will be appreciated by those knowledgeable with such large agricultural equipment, at least some of the row units mounted on the wing sections receive particulate material from the material hopper on the main section. The conduits or tubing leading from the hopper to the individual row units mounted on the wing sections has to be extra long to allow the wing sections to be folded relative to the main section. While the materials passing from the hopper toward the individual row units is carefully metered, the additional lengths of tubing required to allow the wing section to move to a folded position can be detrimental to the accuracy of material flow toward the row units. As an example, in a planter, the additional lengths of tubing could be detrimental to the accuracy of the flow of seed toward the row unit. Accordingly, the additional length of tubing could be detrimental to the seed spacing accuracy. Moreover, the additional length of tubing tends to crimp as a result of the folding movement of the wing section relative to the main section thereby inhibiting the flow of material through the tubing.
U.S. Pat. No. 4,843,983 discloses a pneumatic delivery system having telescoping tube sections in an attempt to solve the problem associated with elongated tubes leading between the hopper and the individual row units on the implements. Such a design, however, normally requires the tubing to be relatively rigid to allow the telescoping ends of the tubes to cooperate with each other. Of course, rigid telescoping tubes are subjected to breakage problems especially in an environment such as planters wherein the tubes are susceptible to damage and possible breakage as the farmer moves thereabout. Rigid tubes normally have a larger diameter than other forms of tubings. Of course, both the movable wing section and main section of the implement must be on relatively level ground surfaces in order for the telescoping tubes to properly orientate themselves relative to each other when the wing section is folded into an operable position relative to the main section of the implement.
To effect telescoping movements between the tube sections, one tube must have a smaller diameter than the other tube with which it is adapted to telescope. Accordingly, a circumferential step of decreased diameter is inherently formed on the inside of the telescoping tubes. The step formed between the telescoping sections of the tubes can prove problematical in that such a step obstructs free passage of relatively light material moving therepast. Those implements having wing sections which horizontally move about a generally vertical axis spaced inwardly from the distal ends of the tool bar associated with the main section further complicates the ability of the rigid tubes to accurately align and telescope relative to each other.
Thus, there remains a need and a desire for a system for delivering material to individual row units arranged on an implement including at least one wing section having row units thereon and which is foldable relative to a main section of the implement.